Electrical machines

摘要

An ac synchronous electrical machine includes a stator and a multi-phase stator winding that defines a plurality of stator poles. The stator winding has two or more coil groups, each coil group including a plurality of coils for each phase that are received in winding slots in the stator. The stator winding is connected to a power source/sink. The coil groups are connected in series and each coil group is connected to a power source/sink by a respective switch (26a, 26b . . . ). This allows one or more of the coil groups to be selectively supplied with power from the associated power source/sink or selectively supply power to the associated power source/sink. The switches are operated by a controller. The coils in each coil group are arranged substantially symmetrically around the circumference of the stator to define selected poles of the electrical machine and to produce a constant and balanced rotating torque when any particular coil group or combination of coil groups is active.

主权项

1. An electrical machine comprising:
a multi-phase stator (i) including two or more coil groups and (ii) formed of sub-windings, each sub-winding corresponding to one of the phases; wherein each sub-winding includes a plurality of coils, each coil being (i) part of a multi-phase set, each set being representative of only one of the poles and (ii) associated with one of the coil groups; and wherein each coil group (i) includes a proportion of a total number of coils within the stator and (ii) is configured for coupling to a power source, an end of one of the two or more coil groups being connected to a beginning of the other coil group (ii) and producing a respective proportion of a maximum torque of the electrical machine.